Cement Kilns: Difference between revisions

Line 13:

* Stage 6 - '''Packing and Shipping''': the cement is conveyed from grinding mills to silos where it is then packed in bags.

Not all cement kilns have the total 'end to end' process on site, with some sites producing the clinker for subsequent grinding, blending and packing at a different site. This might include, for example, the introduction of other materials, such as Blast Furnace Slag to produce a Blast Furnace Cement - a highly sulphate resistant cement that can have up to 65% granulated Blast Furnace Slag mixed with the clinker.

Not all cement kilns have the total 'end to end' process on site, with some sites producing the clinker for subsequent grinding, blending and packing at a different site. This might include, for example, the introduction of other materials, such as Blast Furnace Slag to produce a Blast Furnace Cement - a highly sulphate resistant cement that can have up to 65% granulated Blast Furnace Slag mixed with the clinker. Categories of cement materials under BS EN 197-1 <ref>[http://www.bgs.ac.uk/downloads/directDownload.cfm?id=1353&noexcl=true&t=Cement%20raw%20materials%20 Mineral Planning Fact Sheet BGS 2014 Download]</ref> include:

{| class="wikitable"

|-

! Category !! Description !! Proportion of clinker !! Proportion of other materials

|-

| CEM I || Portland cement || 95 to 100% || 0 to 5%

|-

| CEM II || Blended cements (sub-divided depending on the material used, e.g. 'Portland fly ash cement', 'Portland slag cement, 'Portland limestone cement' etc || 65 to 94% || 6 to 35%

|-

| CEM III || Blastfurnace cement (incorporating ground granulated blastfurnace slags or GGBS || 5 to 64% || 35 to 95%

|-

| CEM IV || Pozzolanic cement (incorporating natural or synthetic pozzolanic material e.g. volcanic ash) || 45 to 89% || 11 to 55%

|-

| CEM V || Composite cement (incorporating both GGBS and pozzolanic material) || 20 to 64% || 18 to 50% GGBS; 18 to 50% Pozzolanic material

|}

==Use of Waste - Historical Context==

The introduction of waste materials - or 'Alternative Raw Materials' as coined by the industry - can be as part of the kiln phase or the final grinding stage and it can be used as an additive or as a fuel in the process.

@@ Line 13: / Line 13: @@
 * Stage 6 - '''Packing and Shipping''': the cement is conveyed from grinding mills to silos where it is then packed in bags.
-Not all cement kilns have the total 'end to end' process on site, with some sites producing the clinker for subsequent grinding, blending and packing at a different site. This might include, for example, the introduction of other materials, such as Blast Furnace Slag to produce a Blast Furnace Cement - a highly sulphate resistant cement that can have up to 65% granulated Blast Furnace Slag mixed with the clinker.
+Not all cement kilns have the total 'end to end' process on site, with some sites producing the clinker for subsequent grinding, blending and packing at a different site. This might include, for example, the introduction of other materials, such as Blast Furnace Slag to produce a Blast Furnace Cement - a highly sulphate resistant cement that can have up to 65% granulated Blast Furnace Slag mixed with the clinker. Categories of cement materials under BS EN 197-1 <ref>[http://www.bgs.ac.uk/downloads/directDownload.cfm?id=1353&noexcl=true&t=Cement%20raw%20materials%20  Mineral Planning Fact Sheet BGS 2014 Download]</ref> include:
+{| class="wikitable"
+|-
+! Category !! Description !! Proportion of clinker !! Proportion of other materials
+|-
+| CEM I || Portland cement || 95 to 100% || 0 to 5%
+|-
+| CEM II || Blended cements (sub-divided depending on the material used, e.g. 'Portland fly ash cement', 'Portland slag cement, 'Portland limestone cement' etc || 65 to 94% || 6 to 35%
+|-
+| CEM III || Blastfurnace cement (incorporating ground granulated blastfurnace slags or GGBS || 5 to 64% || 35 to 95%
+|-
+| CEM IV || Pozzolanic cement (incorporating natural or synthetic pozzolanic material e.g. volcanic ash) || 45 to 89% || 11 to 55%
+|-
+| CEM V || Composite cement (incorporating both GGBS and pozzolanic material) || 20 to 64% || 18 to 50% GGBS; 18 to 50% Pozzolanic material
+|}
 ==Use of Waste - Historical Context==
 The introduction of waste materials - or 'Alternative Raw Materials' as coined by the industry - can be as part of the kiln phase or the final grinding stage and it can be used as an additive or as a fuel in the process.